Carboxylmethylation of the β subunit of xENaC regulates channel activity

Michael D. Rokaw, Jun M. Wang, Robert S. Edinger, Ora A. Weisz, Daniel Hui, Pamela Middleton, Vadim Shlyonsky, Bakhrom K. Berdiev, Iskander Ismailov, Douglas C. Eaton, Dale J. Benos, John P. Johnson

Research output: Contribution to journalArticle

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Abstract

The action of aldosterone to increase apical membrane permeability in responsive epithelia is thought to be due to activation of sodium channels. Aldosterone stimulates methylation of a 95-kDa protein in apical membrane of A6 cells, and we have previously shown that methylation of a 95-kDa protein in the immunopurified Na+ channel complex increases open probability of these channels in planar lipid bilayers. We report here that aldosterone stimulates carboxylmethylation of the β subunit of xENaC in A6 cells. In vitro translated β subunit, but not α or γ, serves as a substrate for carboxylmethylation. Carboxylmethylation of ENaC reconstituted in planar lipid bilayers leads to an increase in open probability only when β subunit is present. When the channel complex is immunoprecipitated from A6 cells and analyzed by Western blot with antibodies to the three subunits of xENaC, all three subunits are recognized as constituents of the complex. The results suggest that Na+ channel activity in A6 cells is regulated, in part, by carboxylmethylation of the β subunit of xENaC.

Original languageEnglish
Pages (from-to)28746-28751
Number of pages6
JournalJournal of Biological Chemistry
Volume273
Issue number44
DOIs
Publication statusPublished - Oct 30 1998
Externally publishedYes

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Aldosterone
Lipid bilayers
Methylation
Lipid Bilayers
Membranes
Sodium Channels
Permeability
Proteins
Epithelium
Western Blotting
Chemical activation
Cell Membrane
Antibodies
Substrates

ASJC Scopus subject areas

  • Biochemistry

Cite this

Rokaw, M. D., Wang, J. M., Edinger, R. S., Weisz, O. A., Hui, D., Middleton, P., ... Johnson, J. P. (1998). Carboxylmethylation of the β subunit of xENaC regulates channel activity. Journal of Biological Chemistry, 273(44), 28746-28751. https://doi.org/10.1074/jbc.273.44.28746

Carboxylmethylation of the β subunit of xENaC regulates channel activity. / Rokaw, Michael D.; Wang, Jun M.; Edinger, Robert S.; Weisz, Ora A.; Hui, Daniel; Middleton, Pamela; Shlyonsky, Vadim; Berdiev, Bakhrom K.; Ismailov, Iskander; Eaton, Douglas C.; Benos, Dale J.; Johnson, John P.

In: Journal of Biological Chemistry, Vol. 273, No. 44, 30.10.1998, p. 28746-28751.

Research output: Contribution to journalArticle

Rokaw, MD, Wang, JM, Edinger, RS, Weisz, OA, Hui, D, Middleton, P, Shlyonsky, V, Berdiev, BK, Ismailov, I, Eaton, DC, Benos, DJ & Johnson, JP 1998, 'Carboxylmethylation of the β subunit of xENaC regulates channel activity', Journal of Biological Chemistry, vol. 273, no. 44, pp. 28746-28751. https://doi.org/10.1074/jbc.273.44.28746
Rokaw MD, Wang JM, Edinger RS, Weisz OA, Hui D, Middleton P et al. Carboxylmethylation of the β subunit of xENaC regulates channel activity. Journal of Biological Chemistry. 1998 Oct 30;273(44):28746-28751. https://doi.org/10.1074/jbc.273.44.28746
Rokaw, Michael D. ; Wang, Jun M. ; Edinger, Robert S. ; Weisz, Ora A. ; Hui, Daniel ; Middleton, Pamela ; Shlyonsky, Vadim ; Berdiev, Bakhrom K. ; Ismailov, Iskander ; Eaton, Douglas C. ; Benos, Dale J. ; Johnson, John P. / Carboxylmethylation of the β subunit of xENaC regulates channel activity. In: Journal of Biological Chemistry. 1998 ; Vol. 273, No. 44. pp. 28746-28751.
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